1. Technical Field
The present invention relates to a detection apparatus, a calculation apparatus, a measurement apparatus, a detecting method, a calculating method, a transmission system, a program, and a recording medium.
2. Related Art
A broadband signal is sometimes transmitted using a plurality of channels having different frequency bands. If the line length of each channel is different, there is a difference in transmission time for each channel. Furthermore, a difference in phase offset occurs due to the frequency dependency in each channel. As a result, when the signal transmitted by these different channels is reconstructed, there is distortion in the reconstructed signal.
The time difference can be detected by applying a measurement pilot signal to each channel and measuring the amount of time necessary for the pilot signal to be output from each channel. The phase offset can be detected by using the phase of the pilot signal output from each channel and the known phase of the pilot signal. When detecting the time difference and the phase offset independently, however, there is a large error. Furthermore, when using the pilot signal, it is necessary to use additional hardware to generate the pilot signal.
Related background art is disclosed in the documents listed below.    1. Japanese Patent Application Publication No 2007-240170    2. US Patent Application Publication No. 2004/0,128,076 A1    3. K. Takita, T. Aoki, Y. Sasaki, K. Kobayashi, “High-Accuracy Subpixel Image Registration Based on Phase-Only Correlation,” IEICE Trans. Fundamentals, Vol. E86-A, No. 8 August 2003.